https://www.luogu.com.cn/problem/P5708#submit
//#include<bits/stdc++.h>
//using namespace std;
//
//int main() {
//
//    double a, b, c;
//    cin >> a >> b >> c;
//    double p = 1.0 / 2.0 * (a + b + c);
//    double ans = sqrt(p * (p - a) * (p - b) * (p - c));
//    printf("%.1lf", ans);
//    return 0;
//}


https://www.luogu.com.cn/problem/P5706#submit
//#include<iostream>
//using namespace std;
//
//int main() {
//    double t;
//    int n;
//    cin >> t >> n;
//
//    printf("%.3lf\n", t / n);
//    cout << n * 2 << endl;
//    return 0;
//}

https://www.luogu.com.cn/problem/P5705#submit
//#include<iostream>
//#include<string>
//using namespace std;
//
//
//int main() {
//
//    string s;
//    cin >> s;
//    for (int i = s.size() - 1; i >= 0; i--) {
//        cout << s[i];
//    }
//    return 0;
//}


https://www.luogu.com.cn/problem/P5704#submithttps://www.luogu.com.cn/problem/P5704#submit
//#include<iostream>
//using namespace std;
//
//int main() {
//    char ch;
//    cin >> ch;
//    cout << (char)(ch - 32) << endl;
//    return 0;
//}

https://www.luogu.com.cn/problem/P5703#submit
//#include<iostream>
//using namespace std;
//
//
//int main() {
//    long long a, b;
//    cin >> a >> b;
//    cout << a * b << endl;
//    return 0;
//}

https://www.luogu.com.cn/problem/B2005#submit
//#include<iostream>
//using namespace std;
//
//int main() {
//    char ch;
//    cin >> ch;
//    printf("  %c\n", ch);
//    printf(" %c%c%c\n", ch, ch, ch);
//    printf("%c%c%c%c%c\n", ch, ch, ch, ch, ch);
//    return 0;
//}



https://www.luogu.com.cn/problem/P1001
//#include<iostream>
//using namespace std;
//
//int main() {
//    long long a;
//    long long b;
//    cin >> a >> b;
//    cout << a + b << endl;
//    return 0;
//}

https://www.luogu.com.cn/problem/P1000#submit

//#include<stdio.h>
//int main() {
//    printf(
//        "                ********\n"
//        "               ************\n"
//        "               ####....#.\n"
//        "             #..###.....##....\n"
//        "             ###.......######              ###            ###\n"
//        "                ...........               #...#          #...#\n"
//        "               ##*#######                 #.#.#          #.#.#\n"
//        "            ####*******######             #.#.#          #.#.#\n"
//        "           ...#***.****.*###....          #...#          #...#\n"
//        "           ....**********##.....           ###            ###\n"
//        "           ....****    *****....\n"
//        "             ####        ####\n"
//        "           ######        ######\n"
//        "##############################################################\n"
//        "#...#......#.##...#......#.##...#......#.##------------------#\n"
//        "###########################################------------------#\n"
//        "#..#....#....##..#....#....##..#....#....#####################\n"
//        "##########################################    #----------#\n"
//        "#.....#......##.....#......##.....#......#    #----------#\n"
//        "##########################################    #----------#\n"
//        "#.#..#....#..##.#..#....#..##.#..#....#..#    #----------#\n"
//        "##########################################    ############\n"
//    );
//    return 0;
//}


https://www.luogu.com.cn/problem/B2025#submit
//#include<iostream>
//using namespace std;
//
//
//int main() {
//    cout << "  *" << endl;
//    cout << " ***" << endl;
//    cout << "*****" << endl;
//    cout << " ***" << endl;
//    cout << "  *" << endl;
//    return 0;
//}


https://www.luogu.com.cn/problem/B2002#submit
//#include<iostream>
//using namespace std;
//
//int main()
//{
//    cout << "Hello,World!" << endl;
//    return 0;
//}